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This article revisits the development of the protoplasm concept as it originally arose from critiques of the cell theory, and examines how the term “protoplasm” transformed from a botanical term of art in the 1840s to the so-called “living substance” and “the physical basis of life” two decades later. I show that there were two major shifts in biological materialism that needed to occur before protoplasm theory could be elevated to have equal status with cell theory in the nineteenth century. First, I argue that biologists had to accept that life could inhere in matter alone, regardless of form. Second, I argue that in the 1840s, ideas of what formless, biological matter was capable of dramatically changed: going from a “coagulation paradigm” (Pickstone, 1973) that had existed since Theophrastus, to a more robust conception of matter that was itself capable of movement and self-maintenance. In addition to revisiting Schleiden and Schwann’s original writings on cell theory, this article looks especially closely at Hugo von Mohl’s definition of the protoplasm concept in 1846, how it differed from his primordial utricle theory of cell structure two years earlier. This article draws on Lakoff and Johnson’s theory of “ontological metaphors” to show that the cell, primordial utricle, and protoplasm can be understood as material container, object, and substance, and that these overlapping distinctions help explain the chaotic and confusing early history of cell theory.  相似文献   

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《Endocrine practice》2018,24(12):1086-1092
Objective: To review literature and present a schematic approach to hypophosphatasia (HPP) evaluation and management applicable to practicing physicians to ease its recognition and diagnosis.Methods: Studies were obtained from online databases PubMed and MEDLINE using keyword ‘hypophosphatasia.’Results: HPP is a rare disease characterized by low serum alkaline phosphatase along with diverse musculoskeletal symptoms that mimic different disorders. To date, the prevalence of HPP and its impact on adults has been unrecognized. There is lack of evidence from larger and long-term studies examining the adult type of this condition.Conclusion: It is essential to increase awareness on the complexity of the pathophysiology and clinical features of HPP, which causes debilitating physical conditions that severely affects quality of life. A better comprehension of adult forms of HPP is essential to reduce a delay in diagnosis as well as ensure suitable management.Abbreviations: ALP = alkaline phosphatase; HPP = hypophosphatasia; PEA = phosphorethanolamine; PLP = pyridoxal-5-phosphate; PPi = inorganic pyrophosphate; TNSALP/TNAP = tissue-nonspecific alkaline phosphatase  相似文献   

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Recent sustainability science research focuses on tradeoffs between human well-being and stress placed on the environment from fossil fuel consumption, a relationship known as the carbon intensity of well-being (CIWB). In this study we assess how the effect of economic development on consumption-based CIWB—a ratio of consumption-based carbon dioxide emissions to average life expectancy—changed from 1990 to 2008 for 69 nations throughout the world. We examine the effect of development on consumption-based CIWB for the overall sample as well as for smaller samples restricted to mostly high-income OECD nations, Non-OECD nations, and more nuanced regional samples of Non-OECD nations in Africa, Asia, and Latin America. We find that the effect of economic development on CIWB increased through time for the overall sample. However, analyses of the Non-OECD and OECD samples indicate that while the effect of development on CIWB increased from null to a moderate level for the Non-OECD nations, the effect of economic development was much larger, relatively stable through time, and more unsustainable for the OECD nations. Additional findings reveal important regional differences for Non-OECD nations. In the early 1990s, increased development led to a reduction in CIWB for Non-OECD nations in Africa, but in more recent years the relationship changed, becoming less sustainable. For the samples of Non-OECD nations in Asia and Latin America, we find that economic development increased consumption-based CIWB, and increasingly so throughout the 19 year period of study.  相似文献   

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Abstract

The mortality patterns of men and women of working age, in terms of the major causes of death, have changed over the past three decades. This study assesses the extent to which mortality among persons of working age represents an economic loss to society. This economic loss is measured by the per capita loss of productive working life, defined as the number of years, on the average, a person can expect to be an active member of the labor force. Causes of death affecting primarily older Americans (heart disease, cancer, stroke) had a relatively small and declining impact on the working lives of men and women. Major causes of death affecting the young (motor vehicle accidents, homicide, AIDS), although accounting for fewer deaths, were responsible for many more years of lost productivity. Gender and socioeconomic differentials in mortality suggest that different strategies are necessary for future reductions in lost work‐years.  相似文献   

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Smart A  Martin P  Parker M 《Bioethics》2004,18(4):322-343
A key selling point of pharmacogenetics is the genetic stratification of either patients or diseases in order to target the prescribing of medicine. The hope is that genetically 'tailored' medicines will replace the current 'one-size-fits-all' paradigm of drug development and usage. This paper is concerned with the relationship between difference and justice in the use of pharmacogenetics. This new technology, which facilitates the identification and use of difference, has, we shall argue, the potential to lead to injustice either by the inappropriate use of difference or through the inappropriate failure to use difference. We build on empirical data from a detailed study of the range of options for the development of pharmacogenetics to present a consideration of the ethical issues that surround patient and disease stratification. In it we explore the ways in which the use of pharmacogenetics may lead to the creation of new, genetically stratified, forms of difference and new forms of injustice based on these divisions. We also examine the ways in which existing forms of difference and social stratification may interact with the use of pharmacogenetics. In conclusion, we suggest how an understanding of these ethical issues could usefully inform future policy discussions.  相似文献   

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Background

Oral contraceptives are known to influence the risk of cancers of the female reproductive system. Evidence regarding the relationship between injectable contraceptives and these cancers is limited, especially in black South Africans, among whom injectable contraceptives are used more commonly than oral contraceptives.

Methods and Findings

We analysed data from a South African hospital-based case–control study of black females aged 18–79 y, comparing self-reported contraceptive use in patients with breast (n = 1,664), cervical (n = 2,182), ovarian (n = 182), and endometrial (n = 182) cancer, with self-reported contraceptive use in 1,492 control patients diagnosed with cancers with no known relationship to hormonal contraceptive use. We adjusted for potential confounding factors, including age, calendar year of diagnosis, education, smoking, alcohol, parity/age at first birth, and number of sexual partners. Among controls, 26% had used injectable and 20% had used oral contraceptives. For current and more recent users versus never users of oral or injectable contraceptives, the odds ratios (ORs) for breast cancer were significantly increased in users of oral and/or injectable contraceptives (OR 1.66, 95% CI 1.28–2.16, p<0.001) and separately among those exclusively using oral (1.57, 1.03–2.40, p = 0.04) and exclusively using injectable (OR 1.83, 1.31–2.55, p<0.001) contraceptives; corresponding ORs for cervical cancer were 1.38 (1.08–1.77, p = 0.01), 1.01 (0.66–1.56, p = 0.96), and 1.58 (1.16–2.15, p = 0.004). There was no significant increase in breast or cervical cancer risk among women ceasing hormonal contraceptive use ≥10 y previously (p = 0.3 and p = 0.9, respectively). For durations of use ≥5 y versus never use, the ORs of ovarian cancer were 0.60 (0.36–0.99, p = 0.04) for oral and/or injectable contraceptive use and 0.07 (0.01–0.49, p = 0.008) for injectable use exclusively; corresponding ORs for endometrial cancer were 0.44 (0.22–0.86, p = 0.02) and 0.36 (0.11–1.26, p = 0.1).

Conclusions

In this study, use of oral and of injectable hormonal contraceptives was associated with a transiently increased risk of breast and cervical cancer and, for long durations of use, with a reduced risk of ovarian and endometrial cancer. The observed effects of injectable and of oral contraceptives on cancer risk in this study did not appear to differ substantially. Please see later in the article for the Editors'' Summary  相似文献   

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Culture, Medicine, and Psychiatry - Often, we assume the traumatic nature of first response work has inevitable repercussions. This can lead to assumptions about trauma being the reason for...  相似文献   

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Lippia species are widely used as traditional remedies by many South African communities. The identification of Lippia spp. indigenous to South Africa is currently based on the morphology and geographical origin of the specimen. However, morphological similarities are evident and due to sympatric distributions, different species may co-occur in the same natural environment, thereby presenting difficulties in the taxonomic delimitation of these taxa. In this paper, gas chromatography–mass spectrometry (GC–MS) and vibrational spectroscopic analyses were used to investigate the chemotaxonomic differentiation of four Lippia species (L. javanica, L. scaberrima, L. rehmannii and L. wilmsii), based on the essential oil composition. The results demonstrate that multivariate classification of chromatographic data enabled separation of Lippia oils into three distinct clusters representing L. scaberrima, L. rehmannii and L. javanica. With the aid of chemometric algorithms, it was also possible to use both mid infrared (MIR) and near infrared (NIR) spectroscopy for a clear distinction of the Lippia spp., with results comparable to those obtained by GC–MS. Orthogonal projections to latent structures (OPLS) presented a better classification algorithm than principal component analysis (PCA), in both GC–MS and spectroscopy analyses. Chemical variations within the Lippia spp. complex were evident, particularly for L. javanica and L. scaberrima, which exhibited significant intra-species variation.  相似文献   

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In 8 Versuchen wurde der Gärungsverlauf bei der Silierung von nitratarmem Grünfutter von Welschem Weidelgras, Knaulgras und Gras‐Leguminosen‐Gemenge geprüft. Aus den Ergebnissen geht hervor, daß bei Fehlen von Nitrat im Grünfutter bereits zu Gärbeginn Buttersäure entsteht, parallel zur Milchsäuregärung, auch in leicht vergärbarem Grünfutter. Diese frühzeitige Buttersäurebildung ist mit dem Fehlen von Nitrat als natürlicher Clostridieninhibitor zu erklären. Die Clostridienentwicklung verläuft zu Gärbeginn demnach wesentlich schneller als bisher angenommen wurde. Offensichtlich dienen leicht lösliche Kohlenhydrate als Substrat für die Buttersäurebildung. In nitratarmem Grünfutter werden deshalb Clostridien als Nahrungskonkurrenten für die Milchsäurebakterien wirksam. Aminosäuren werden zu Gärbeginn nicht abgebaut. Trotz z.T. hoher Buttersäuregehalte sind die Ammoniakgehalte gering. Höhere Homologe der Buttersäure fehlen. Die Milchsäuregärung erreicht trotz hoher Zuckergehalte im Grünfutter meist nur ein begrenztes Ausmaß. Es werden Unterschiede in der Vergärbarkeit der Kohlen‐hydratfraktion zwischen den Gräsern angenommen.  相似文献   

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This article analyses the Urban Poverty and Family Life Survey of Chicago and an urban subsample of the National Survey of Families and Households to examine race and ethnic variation in the occurrence and consequences of birth versus marriage pathways to family formation. Results based on multiple‐decrement life table analysis and multi‐variate life table regression analysis reveal strong race and poverty effects on pathways to family formation, but Hispanic origin does not systematically influence the odds that women will enter family life via marriage versus birth. We show stronger race effects on pathways to family formation for the Chicago sample owing to the much higher incidence of teen parenting among black inner‐city residents. Results also suggest lasting economic consequences of non‐marital fertility, irrespective of whether women eventually marry or divorce subsequent to a premarital birth.  相似文献   

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The aim of this study was to explore the effect of butylphthalide on the brain edema, blood–brain barrier of rats of rats after focal cerebral infarction and the expression of Rho A. A total of 195 sprague–dawley male rats were randomly divided into control group, model group, and butylphthalide group (40 mg/kg, once a day, by gavage). The model was made by photochemical method. After surgery 3, 12, 24, 72, and 144 h, brain water content was done to see the effect of butylphthalide for the cerebral edema. Evans blue extravasation method was done to see the changes in blood–brain barrier immunohistochemistry, and Western blot was done to see the expression of Rho A around the infarction. Compared with the control group, the brain water content of model group and butylphthalide group rats was increased, the permeability of blood–brain barrier of model group and butylphthalide group rats was increased, and the Rho A protein of model group and butylphthalide group rats was increased. Compared with the model group, the brain water content of butylphthalide group rats was induced (73.67 ± 0.67 vs 74.14 ± 0.46; 74.89 ± 0.57 vs 75.61 ± 0.52; 77.49 ± 0.34 vs 79.33 ± 0.49; 76.31 ± 0.56 vs 78.01 ± 0.48; 72.36 ± 0.44 vs 73.12 ± 0.73; P < 0.05), the permeability of blood–brain barrier of butylphthalide group rats was induced (319.20 ± 8.11 vs 394.60 ± 6.19; 210.40 ± 9.56 vs 266.40 ± 7.99; 188.00 ± 9.22 vs 232.40 ± 7.89; 288.40 ± 7.86 vs 336.00 ± 6.71; 166.60 ± 6.23 vs 213.60 ± 13.79; P < 0.05), and the Rho A protein of butylphthalide group rats was decreased (western blot result: 1.2230 ± 0.0254 vs 1.3970 ± 0.0276; 1.5985 ± 0.0206 vs 2.0368 ± 0.0179; 1.4229 ± 0.0167 vs 1.7930 ± 0.0158;1.3126 ± 0.0236 vs 1.5471 ± 0.0158; P < 0.05). The butylphthalide could reduce the brain edema, protect the blood–brain barrier, and decrease the expression of Rho A around the infarction.  相似文献   

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In light of the tendency to present the arts in an integrated fashion in many education systems worldwide, this article examines the consequences of integration for discrete art forms. In particular, we investigate the advantages of adopting a syntegrated approach to the facilitation of arts in teacher preparation. A specific comparison between the implementation of arts curricula in South Africa and Australia is made. The disjuncture between policy and practice in arts education that has been reported internationally needs constant monitoring. We conclude that the heart of curriculum transfer and transformation lies in the classroom.  相似文献   

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Conclusion and Issues for Further Investigation This last result leads, rather naturally, to some concluding observations and a series of questions for further investigation. These case studies show that in all of the sites examined, the institutionalization of molecular biology as a discipline was primarily driven by the need to separate groups of practitioners with divergent but overlapping interests within the local context. Thus molecular biology was contingently separated from agricultural or medical biochemistry, virology, work on the physiology of nucleic acids, and so forth for contingent local institutional reasons. This makes it even more pressing to try to understand how molecular biology came to be delimited on a larger scale. How did it come to be a discipline with specific intellectual content (or did it?), including some problems, tools, and practices and excluding others? How did it gain authority as the forefront biological science by the mid-1960s? We need to understand the ways in which the tensions between different practices, projects, aims, understandings of the goals of molecular biology, and so on were resolved, on what scale and in what venues, so that something approximating the political character of a discipline, rather than a federation, was achieved. If these case studies provide a sound starting point, it will nevertheless prove difficult to answer the interconnected questions implicit here satisfactorily.One means of getting at such questions that should prove of considerable interest is to examine carefully the work of those who were widely cited in the papers of the late fifties through the mid-seventies by the people now considered major founders of molecular biology. By studying the contributions of those who are now omitted in the standard histories and recollections, we will gain a clearer sense of the possibilities that were open as molecular biology took shape. It is already widely recognized that the contributions of a number of biochemists have been given short shrift, but (as the example of Ernest Gale in Rheinberger's study illustrates) there are a great many more figures whose line of work were then crucial but who are now overlooked.6 To understand both what molecular biology was at the time of its early institutionalization and what is has become, it will be enormously helpful to understand at what point the definition or ideology hardened and the grounds for inclusion and exclusion of individuals and lines of work were reformed. Studies of this sort are appropriate in many other areas as well, of course; in general, they should different histories, political standing, and institutional bases of those disciplines in their national cultures. It is likely (but a matter for investigation!) that such differences influenced the opportunities for introducing new bench practices, if in no other way than by delimiting the niches within which certain practices could be initiated.7 And since new practices can fail to achieve their objectives, can transform the direction of work and disciplinary allegiances of their practitioners, can lead to only routine results, or can open up important new vistas, the character of the available niches from which to work can prove to have a strong influence on the direction that new work takes if and when it starts to flourish. A key aspect of this problematic (not yet adequately studied, I believe) is the problem of drawing boundaries between different kinds of work and determining where each should fit among established disciplines and/or within some new construct. To the extent that an international solution is ultimately achieved to such problems, it must surely be achieved in light of initially different ways of dealing with it in different countries.Underlying work of the sort we have been exploring is the thorny problem of how best to contextualize the work being studied. This, I believe, is one of the major historiographic problems that we must face in the history of science. It is by no means a new problem, of course, but a particularization of the age-old problem of the (seeming) overdetermination of historical events. If we deal with local cultures, to understand how they develop and their fate we need to understand their location within larger cultures. But it is utterly unclear how to draw appropriate boundaries on the relevant larger culture(s). As even this brief discussion has shown, institutional cultures, the cultures of sponsoring agencies, the culture of science (or of biological science, physical science, etc., as appropriate), and national cultures all can provide relevant contexts, all can occasionally determine the fate of work undertaken in a particular local context. The potentially intractable problem of delimiting the boundaries of investigation looms large here, but it is one that must be faced explicity if we are to profit fully from the enormously stimulating investigations of local cultures exemplified in the four papers published in this symposium. My own view is that we have no abstract standard available for determining which boundaries are appropriate to a given study, and, indeed, that no single contextualization is adequate to the examination of any given case, but that, nonetheless, we can (at least sometimes) distinguish useful and explanatory delimitations of the larger context from others that prove to be misleading.Against this background, I hope that the four papers published in this special issue will stimulate the readers of the JHB to carry out similar studies—that is, studies that seek to characterize and contextualize local experimental cultures —over a wide range of cases. I also hope that some of those who take up this challenge will deal with the larger questions raised by the need to find a way of balancing different, sometimes competing, contextualizations of such studies. The fact that any given case requires multiple contextualizations, resulting in multifaceted representations no one of which is alone adequate, will surely land us in fascinating, hopefully fruitful and productive, controversies.  相似文献   

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The consumption of high-fat and high-sugar diets, in the form of junk food, and binge eating are now common. Increasing evidence suggests that a high-fat diet (HFD) can induce neuroinflammation and alter behavior. I aimed to study the effects of diets of differing fat content on neuroinflammation and spatial memory using an object–place (OP) task. Thirty-two adult male rats were allocated to four groups and fed a regular diet (Regular diet), a control diet (Control diet), an HFD (60% of calories from lard), or a high-coconut oil diet (HCOD; 60% of calories from coconut oil) for 3 days. Their water intake, food consumption, body mass, and metabolic variables were measured. HFD-fed rats showed significantly poorer performance on the OP task, as assessed using the discrimination index (??0.208?±?0.094), than the Regular (0.462?±?0.078; P?<?0.0001) and Control (0.379?±?0.081; P?=?0.0003) groups. However, no significant difference was observed in spatial memory between the HCOD and Regular groups. The concentrations of neuroinflammatory markers (interleukin [IL]-1β, IL-6, tumor necrosis factor α, and nuclear factor κB) were also measured in the hippocampus and prefrontal cortex. HFD-fed rats showed significantly higher levels of neuroinflammatory markers than the Regular and Control diet-fed groups. HCOD feeding did not induce neuroinflammation in the hippocampus and prefrontal cortex compared with the Regular and Control groups.

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